Device for controlling radio apparatus



May 27, 1930. J. NISENSOIAJI 1,760,080

DEVICE FOR CONTROLLING RADIO APPARATUS Filed Aug. 4, 1928 2 Sheets-Sheet J INVENTOR ATTORNEY J. NISENSON 1,760,080

DEVICE FOR CONTROLLING RADIO APPARATUS Filed Aug. 4, 1928 2 Sheets-Sheet 2 INVEI NTOR' ATTORNEY May 27, 1930,

Q r1 g Patented May 27, 1930 UNITED STATES PATENT OFFICE JULIUS NISENSON, OF BROOKLYN, NEW YORK, ASSIGNOR OF ONE-HALF TO AARO CHANIN, OF NEW YORK, Na Y.

DEVICE FOR CONTROLLING RADIO APPARATUS Application filed August 4, 1928. Serial No. 297,502.

This invention relates to radio apparatus and more particularly to means for controlling such apparatus.

The correct tuning of a radio receiving set to receive a given broadcasting station requires care and some skill. This is equally as true with the one-dial control as with the set having a plurality of control dials; al-

though the tuning-in process is simpler with the one-dial control. Since there are certain popular broadcasting stations in the vicinity of every radio receiving set, such station being often preferred and frequently used, a device forautomatically tuning-in such stations would be a source of great convenience and eliminate the task of manually tuning from one station to another.

It is an object of this invention to provide a device by means of which certain preferred broadcasting stations may be automatically selected for reception by a receiving set, at the same time excluding other stations, and not interfering with the normal operation of the set.

It is a further object of the invention to provide a mufiling device to exclude all sounds from the sets during the process of automatically changing from one selected station to another.

A further obj ectis to provide an automatic station selecting device which may be readily applied to any standard radio receiving set without material alteration.

A further object is the provision of an especially constructed solenoid controlled switch adapted to make and break certain connections necessary to the proper operations of the device.

These and other objects are attained by the novel construction, combination and arrangement of parts hereinafter described and shown, in the accompanyin drawing, constituting a material part 0 this disclosure and in which:

Figure 1 is an inverted side view of a switch element used in the control device.

Figure 2 is an inverted end view of the switch element.

Figure 3 is a plan view of the switch element.

The coil 9 is separated from the horizontalportion of the U-member 5 by a disc 10 of insulating material, and a brass plate 13 is separated from coil 8 by a similar disc 11. The plate 13 is attached by screws, or other means, to the flanges 12 integral with the legs of member 5.

A strip ,14 of insulating material is attached to one end of plate 13 and the other end of the plate carries a support 15 to which is fixed a strip. 16 of insulating material. Two resilient strips 17 and 18 are fixed to the strip 16, the strips 17 and 18 being also attached to a plate 19 of insulating material, the plate 19 having fixed to its underside a bar 20 of soft iron which serves as the armature of the electromagnet. The resilient strips 17 and 18 normally hold the armature and its associated parts in a raised position as shown in Fig. 4.

Mounted on the upper side of plate 19 is a block 21 of insulating material to which are attached the three contact arms 22, 23, 24 which are adapted to engage the-contacts 25, 26, 27 respectively, mounted on a block of insulating material 28, the latter being supported by'posts 29 fixed to plate 13. On the underside of the block 28 are two contacts 30, 31 which are engaged'by the contacts 32 and 33 respectively onstrips 17 and 18, contacts 32 and 33 being adapted to also engage contacts 34 and 35 mounted on the strip 14 of insulating material. Attached to contact arms 22, 23, 24 are wires 36, 37 38 which are connected to a gang of three condensers, respectively 39, 4Q, 41, the condensers being adapted to be simultaneously controlled.

Contact 34 is connected by a wire 42 to a small incandescent lamp 43, and strips 17 and 18 are respectively connected by wires 44 and 45 to contact points on another switch elemore than three tubes, there must be a connection to the grid circuit of each tuning tube. Three tubes are herein designated merely by way of example. The same applies to the condensers 39, 40, 41, there being a condenser for each tube in the tuning circuit of the receiving set.

Referring to the diagram in Figure 5 three switch elements are generally designated as i D, E, and F, the elements D and E controllin two pre-selected stations, while element F is or the purpose of placing the receiving set in condition whereby any station may be manually tuned-in by manipulating the usual dials on the set. The diagram shows only the connections for automatically tuning-in two selected broadcasting stations, but obviously the system may be readily extended to pro- 7 vide for the automatic tuning in of any number of stations, a switch element such as shown in Figures 1, 3, being necessary for each selected station.

A source of power at A supplies the A battery current for the filaments of the electron tubes, and the current necessary to energize the solenoids, the current flowing through wire 49 to the coil 8 and thence to coils 8 and 8 and to the arms 18 and 18. The coils 8, 8, 8 are in series, and contacts 30 and 32, are normally in engagement as lik ewise are contacts 30 and 32, and 30 and 32 Inorder to assist in readily understanding the diagram, parts in switch elements E and .Fwhich are similar to parts in switch element D bear the same numeral with the addition of the letter e or f.

It will be seen that current passing through coils 8, 8*, 8 is uninterrupted whenever contacts 30 and 32 of all of the switch elements are in engagement. However, due to the combined resistance of the several coils in series connected. Gonsequently,-when button D is depressed, only the armature of switch element D will be drawn down, the armatures of elements E and F remaining unaffected.

When the armature 20 is drawn down, the arms 22, 23, 24 engage contacts 25. 26, 27 to close the circuit between the three condensers 39, 40, 41 and the grid circuits of the three electron tubes 46, 47, 48 of the radio receiving set.

At the same time arm 17 is drawn down to cause contacts 33 and 35 to close a circuit through the incandescent lamp 43, to indicate to an operator that the apparatus is now in a condition to receive from broadcasting station D. It is not necessary for the operator to hold the button D down, as the closing of the circuit momentarily is suflicient to produce an additional flux necessary to overcome the reluctance of the air gap between the armature 20 and the core 7. When the air gap reluctance has been overcome. coil 9 is no longer needed, as the retention coil 8 produces a flux sufiicient to hold the armature down.

It will be noted that only the switch element with which the depressed button is connected is affected, the other switch elements remaining in their normal positions, with open circuits between their condensers and the grids of the electron tubes. Consequently, the receiving set will pick up only radio waves for which the condensers of element D have been set. In practice the condensers of the various elements are set to receive the various preferred broadcasting stations, and when a particular button is depressed, the desired station is received accurately. The buttons are normally held in a raised position by resilient means.

W In order to'eliminate unpleasant sounds during the process of tuning from one station to another, there is provided an electromagnet having a core 50 and a solenoid 51, the latter being energized when the circuit is completed by depressing either of the buttons D, E, or F. When the solenoid is energized the magnet draws the armature 52 to cause contact 53 to'engage contact 54, the latter being connected to one terminal 55 of a loud speaker or other sound reproducing device connected with the receiving set. The armature 52 is connected with the other terminal 56 of the sound reproducer and when contact 53 engages contact 54, the sound reproducer is short-circuited, thus preventing the reproduction of sounds from the receiving set.

In applyingmy station selecting device to a radio receiving set, the grids of each electron tube in the tuning circuit is connected to contacts such as 25, 26, 27 on the several switch elements. There should be a switch element for each station desired to be automatically tuned-in; also there must be an additional switch element, such as element F to provide for the use of the radio receiving set in the usual manner.

- In operation, a button, for example button D, is'depressed andthe condensers 39, 40, 41 are adjusted to properly tune-in apreferred broadcasting station. This setting of the condensers is maintained and whenever button D is depressed and released, broadcast- .ing station D will be heard, it such station is in operation.

Button E is then depressed and released, and the condensers 39 40, 41 are adjusted to properly bring in broadcasting station E, and the condensers are maintained in the adusted positions.

Condensers 39, 40, 41' are the regular condensers of the radio receiving set, and button F is depressed only whenthe operator desires to tune in stations not previously selected.

Now, when button E is depressed, the con there is no engagement of contact 32 with either contact 30 or contact 34?, thus stopping the flow of current in the series circuit in which coils 8, 8 and 8 are included. Consequently, armature 20 of element D is released and the arms 17 and 18 are allowed to return to the raised position to cause contacts 32 and 33 to respectively engage contacts 30 and 31. The flow of the current through coil 9 produces sufiicient magnetism in thecore 7, meanwhile, to cause the armature to continue its downward movement until it engages the core 7, at which time the contacts 32* and 35 are in engagement, thus re-establishing the flow of current in the series circuit. By this arrangement, previously used switch elements are automatically returned to their normal positions when the button of another switch element is depressed to bring in a station.

Now, when the operator desires. to bring in station D, be momentarily depresses button D to connect condensers 39, 40, 41 with the grids of the electron tubes. At the same time connections are made to light the incandescent lamp 43, and while the button is depressed, the electromagnet 50 and the armature 52 cause the sound reproducer to be short-circuited so that no sounds will be heard until the button is released.

WVhen station E is desired, button E is depressed and released in a similar manner; and when the operator desires to operate the receiving set in the usual manner to bring in various stations at will, the button F is depressed and released. This connects the condensers 39', 40, 41 of the set withthe grids of the electron tubes, and the set is then in condition for operation in the usual manner, the settings of the condensers for selected stations D and E at the same time being unaffected.

In order to prevent receiving sounds from undesired broadcasting stations when no button has been depressed and consequently no switch element has been set, there are provided means for short-circuiting the output transformer of the receiving set. When the switch elements are unset, contacts 31 and 33 are in engagement and there is a circuit from the negative terminal of the A battery to arms 17 to contact 31 to arm 17 to contact 31 thence to arm 17 to contact 31, thence to contact 57 engaging contact 53, thence to terminal 56, which will, obviously, be negative in polarity. Contact 55 is already grounded to the negativeterminal of the A battery, and consequently, the output transformer is short-circuited. It should be noted that this particular short-circuiting device is only effective when none of the switch elements are operating. As soon as a button is depressed and a switch element has been set, the circuit from the negative terminal of the A battery is broken, for arm 17 is drawn down to cause contact 33 to engage contact 34 to complete a circuit through the incandescent lamp 43.

The buttons D, E, F, may be located on the panel of the receiving set, or they may be positioned at a remote point. Obviously, the controlling system herein disclosed may be extended to include any number of selected broadcasting stations, a switch element, condensers, and a button being necessary for each station.

The foregoing disclosure is to be regarded as descriptive and illustrative only, and not as restrictive or limitative of the invention, of which obviously an embodiment may be constructed including many modifications without departing from the general scope herein indicated and denoted in the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. In combination with a radio receiving set having a sound reproducer connected thereto, a device for automatically conditioning said receiving set to'receive radio waves from selected broadcasting stations, comprising a plurality of gangs of variable condensers, there being a gang of condensers for each selected station, means for automatically connecting any selected gang of condensers to the grid elements of the electron tubes in the tuning circuit of the receiving set, and means to short-circuit the sound reproducer during the process of connecting the condensers to the grid elements.

2. In a device for automatically conditioning a radio receiving set to receive radio waves from selected broadcasting stations, said receiving set having a sound reproducer connected thereto, means to short-circuit the sound reproducer during the process of conditioning the set to receive a selected station whereby undesired sounds are prevented.

3. In a device for automatically conditioning a radio receiving set to receive radio waves of predetermined frequencies, an electro-magnetic switch to close a circuit to shortcircuit the output transformer of said receiving set to prevent the reproduction of sounds 5 during the process of conditioning thereceiving set to receive radio waves of a desired v frequency.

4. In combination with a radio receiving set having a sound reproducer connected thereto, a switch bridging the terminals of said sound reproducer, an electromagnet as-- sociated with the switch, means for tuning the receiving set, and means associated with the tuning means to energize the electromagnet to cause the switch to render the sound reproducer ineffective during the tuning process, whereby undesired sounds are prevented.

5. In combination with a radio receiving set having a sound reproducer connected thereto, a device for tuning the receiving set,

and means controlled by said tuning device to short-circuit the sound reproducer during the process of tuning whereby undesired sounds are prevented.

5 In testimony whereof I affix my signature.

JULIUS NISEN SON. 

